cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A245650 Primes in the sequence 12*n - prime(n), (A245071).

Original entry on oeis.org

31, 41, 59, 67, 101, 107, 139, 179, 193, 199, 211, 229, 239, 269, 271, 281, 293, 307, 313, 353, 353, 353, 379, 397, 409, 431, 439, 449, 449, 457, 467, 479, 491, 499, 509, 521, 547, 563, 599, 607, 617, 641, 659, 673, 709, 719, 739, 751, 761, 769, 809, 811, 821, 827, 859, 863, 881, 883, 911, 911, 919, 929
Offset: 1

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Author

Freimut Marschner, Jul 30 2014

Keywords

Comments

As the arithmetic derivative of prime numbers is [prime(n)]' = 1 the comparison of the first arithmetic derivative of (A245071)' = A245649 leads to a selection of 13.386 prime numbers out of 100.000, where some prime numbers are repeated. Remark: The sign of prime(n) here used is +, so prime(n) is distributed relative to 12 = floor(prime(n)/n).
Since 12*i - prime(i) < 0 for i > A102281(12) = 40121, this sequence is finite. It has 13386 members, with 1793 distinct primes, the largest being 16369 = a(4713). - Robert Israel, Jul 30 2014

Crossrefs

Programs

  • Maple
    A:=select(isprime, [seq(12*n - ithprime(n), n=1..40121)]); # Robert Israel, Jul 30 2014
  • PARI
    for(n=1,10^3,q=12*n-prime(n);if(isprime(q),print1(q,", "))) \\ Derek Orr, Jul 30 2014

Formula

a(n) is the n-th prime member of the sequence 12*i - prime(i). a(n) = prime(n) if (12*i - prime(i)) = prime(n).
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